(A) Endogenous Cop1 was immunoprecipitated from wild-type MEFs and DKO MEFs. Cell extracts (CE) and immunoprecipitates (IP) were analyzed by immunoblotting. Roman numbers indicate different exposure times: I, short exposure; II, long exposure.
(B) Endogenous Cop1 was immunoprecipitated from DKO MEFs infected with lentiviruses expressing untagged human Cry2 under the control of a doxycycline-inducible promoter. CEs and immunoprecipitates were analyzed by immunoblotting.
(C) HEK-293T cells were transfected with HA-tagged Cop1 together with either an empty vector (EV) or with either Cry1 or Cry2 expressing vectors and immunoprecipitated from CEs with an anti-HA resin. CEs and immunoprecipitates were analyzed by immunoblotting.
(D) HA-tagged Det1 was co-expressed in HEK-293T cells with either EV, wild-type Cry2, or Cry2-N130 and immunoprecipitated from CEs with an anti-HA resin. CEs and immunoprecipitates were then analyzed by immunoblotting.
(E) The experiment was performed as in (D), except that increasing amounts of wild-type Cry2 expressing vector were transfected. See also Figures S4 and S5.